Bacterial aggregation on the teeth known as plaque has been identified as a cause of dental caries, gingivitis, periodontitis and other gum diseases. Mechanical methods have been used for sometime for the prevention of dental plaque but have not generally achieved sufficient results. Studies have shown that mechanical methods such as the use of dental floss and interspace brushes do not eliminate interproximal plaque. During the past decade or more chemical plaque control as a substitute or supplement to mechanical methods has been tried.
Octapinol has been tested for its ability to reduce plaque formation and the development of gingivitis by Willard, Edwardsson, Attstom and Matsson, "The effect of Octapinol on dento-gingival plaque and development of gingivitis", Journal of Periodontal Research, Volume 18, pages 429-437, (1983). Here it is reported that octapinol may prevent the development of plaque. Some adverse side effects of octapinol are its toxicity, lasting bitter taste and its brownish staining of the teeth.
U.S. Pat. No. 4,636,382 describes morpholino compounds which are useful for the inhibition or removal of dental plaque. The '382 patent also discloses that a wide variety of chemical and biological agents have been suggested for the inhibition of plaque, such as penicillin, chlorohexidine, 8-hydroxyquinoline and ethylenediamine tetraacetate. However, many of these chemical and biological agents are described as exhibiting insignificant effects and often causing serious side effects. The morpholino compounds of the '382 patent are described as having a low antibacterial effect and lacking undesirable side effects such as discoloration of the teeth.
U.S. Pat. No. 4,610,871 describes the use of monoalkyl or dialkyl ethers of dianhydrohexitols to inhibit the formation of plaque and calculus on teeth. U.S. Pat. No. 4,178,363 describes the use of n-undecylenic acid or a calcium or zinc salt thereof for reducing dental plaque and infections of the teeth and gums. U.S. Pat. N. 4,119,711 describes spiro 1-(hydroxyalkyl)-piperidino derivatives which have efficacy in reducing the formation of plaque. U.S. Pat. No. 3,976,765 describes bis-biguanido hexanes in combination with nonionic surfactants and certain foam stabilizers for use in a variety of oral preparations.
Additionally, U.S. Pat. No. 3,887,712 discloses that alexidine dihydrofluoride is useful in the treatment of dental plaque, calculus, gingivitis and related periodontal diseases. U.S. Pat. No. 4,160,821 discloses that a glycerine solution of zinc chloride or other acceptable zinc salts provides effective therapy for gingivitis when applied to the gingivae and teeth.
Efforts continue toward finding improved means for reducing and/or eliminating plaque without many of the side effects associated with the prior art, such as discoloration of teeth or tongue, desquamation and soreness of oral mucosa, objectionable taste, toxicity and imbalance of the oral flora. It is an object of the present invention to provide novel compositions which are useful in the treatment of plaque and gingivitis without many of the adverse side effects associated with prior art compositions. It is another object of this invention to provide anti-plaque compositions which would cause little or no ecological imbalance of the oral flora. It is a further object of this invention to provide compositions comprising a combination of a morpholinoamino alcohol and metal salts wherein these compositions possess synergistically improved anti-plaque and anti-gingivitis activity.